Device for automatic lathes



April 29, 1947. E. BODMER DEVICE FOR AUTOMATIC LATHE Filed Aug. 26, 1943 5 Sheets-Sheet l gdb?" 5 Sheets-Shee 2 Filed Aug. 26, 194.51

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mm wa April 29, 1947- E. BODMER DEVICE FOR AUTOMATIC LATHE Filed Aug. 26, 1943 5 Sheets-Sheet 3 EBA/EST BODME'Q,

April 29, 1947. E BODMER 2,419,704

DEVICE FOR AUTOMATIC LATHE Filed Aug. 26, 1943 5 sheets-sheetl;

'//VI/E/VTU/QJ April 29, 1947. E. BODMER DEVICE FOR AUTOMATIC LATHE 5 Sheets-Sheet 5 Filed Aug. 26, 1943 Patented Apr. 29, 1947 DEVICE FOR AUTOMATIC `LATHES Ernest Bodmer, Geneva, Switzerland Application August 26, 1943, Serial No. 500,12 In Switzerland June 20, 1942 Claims.

Automatic lathes are generally equipped with several tool-holders arranged as a star about the spindle, according to radial planes passing through the center of it. Many lathes are moreover equipped with a turret-shaped tool-holder, working in the axis of the spindle.

Among the several tool-holders disposed in a fan-like position `about a spindle, three main different tool-holders are to be mentioned:

(a) A tool-holder for performing turning-off work or traversing work, arranged on the front guide way of the bench of a lathe and equipped with two cross slides, itbeing possible to provide this tool-holder with accessory apparatus such as copying devices and screw thread cutting contrivances;

(b) A cross or surfacing tool-holder, arranged on the rear guide way of the lathe bench and equipped with two cross slides;

(c) A parting or cutting tool-holder, arranged vertically and resting against the face of the fast head stock. This tool-holder is fitted with one single slide, the translation motion of which is performed in a plane perpendicular to the axis of the spindle.

Some designers have provided auxiliary toolholders placed between the three above mentioned tool-holders.

These auxiliary tool-holders are provided for performing surfacing work which require small strains.

Such lathes permit the performance of operations involving heav57 strains such las bearing or transverse operations in which the front toolholder is employed, and p-arting or cutting operations in which the rear tool-holder is utilized. The auxiliary tool-holders are used on work in which strains of a lesser degree are encountered such as, for example, in chamfering operations.

It is possible to perform a rough traversingV operation by means of the front tool-holder, and a finishing traversing operation by means of the rear tool-holder. In this case, however, it is no longer possible to perform a parting or cutting o operation requiring a great strain.

It is also possible to cut a screw thread by means of the front tool-holder controlled by a screw-cutting contrivance, or a cone by means of this tool-holder controlled by a copying contrivance. In these cases, the rear tool-holder may either perform a parting or cutting-off operation, or the roughing out of .a bearing surface, but it is no longer possible to perfo-rm two operations requiring great strains.

The present invention embodies a device for an automatic lathe equipped with, at least one tool-holder for performing a turning off or traversing operation and a tool-holder for a parting or cutting oif operation. The device eliminates the mentioned inconveniences inasmuch as it is equipped with an auxiliary turning off or traversing tool-holder with cross slides, controlled independently of the other tool-holders of the lathe and fixed on a support fastened to the lathe, this support being arranged with regard to the other tool-holders, in such a way that the auxiliary tool-holder might be used simultaneously with any one of these mentioned tool-holders.

The here attached drawing shows, by way of example only, two forms of embodiment of the device for an automatic lathe, referring to the present invention.

Fig. 1 is a perspective view of one embodiment;

Fig. 2 is a diagrammatic representation of the device shown in Figure 1.

Fig. 3 is a detailed view;

Fig. 4 is a detailed partial sectional view according to the line III--III of Fig. 2 and the line C-C of Fig. 8;

Fig. 5 is a detailed View with parts in section.

Fig. 6 is a front view of the guide;

Fig. 7 is a perspective view of a second embodiment; l

Fig, 8 is a view showing the arrangement of the slide bearing the tool-holder with respect to the spindle and to the other tool-holders of the lathe.

In the embodiment illustrated in Figs. l and 2, the device is arranged as a thread-cutting con-l trivance. It has a frame I intended to be xed on the bed of the lathe by means of fastening elements 2. This frame is equipped with a support 3 for a tool-holder arranged on cross-slides, as Well as the necessary elements for controlling the motion of the tool-holder for cutting screw threads. The starting of the screw-cutting device is controlled, according to known devices, by a cam 5 arranged on a cam shaft 4 of the lathe.

A reciprocating lever 8 with two rest positions, bears a linger 'I which engages against the cam faces I0 and Ita of the cam 5. Each of the cam faces I0 and Ia is formed from one of the faces of adjustable dogs IIJband IIlc. 'These dogs are fixed in their actually required position by known devices. The cam face Il), upon rotation of the shaft 4, engages'the finger 'l which is rigidly secured to the bifurcated lever 8 and rotates the lever 8 in Ia clockwise direction about its pivotal axle 9. An element I I, adjustable in its position, is fastened on one of the arms of the lever 8, and acts on a lever I2 pivoted on I3 yon the frame I.

lIhe oscillation of this lever l2 causes the throwing in of both parts of a clutch I4, one part of of which is in mesh with a set of interchangeable toothed wheels lla-lb-flc whereas the other l displaced and when moved causes a correspond "ing movement of the slide 28 whose motion axis in,`

i parallel thereto. Slide 28 has a transverse groove 88 (Fig. d) in which dsplaceably fits an engaging i member 39 terminally carried Vby rod 44 and "which communicates the'm'ovements of rod 44 to slide 28 without preventing radial displacement ofslide '28. lT Tl're'guide 4f2isjxedonrthe slide 46 jbymeans of two screws '45Lwhich traverse 'slots one |9 meshes with a toothed gear |9a Xed onk a shaft 2|.

controlling, by the intermediary of ay toothed wheel |90, a toothed wheel `|9d-mountedloose onv 1 a shalt 22. The sets of toothed wheelsV i'and I9 are arranged in such a way that the Itoothed wheel |901 revolves in the Yreverse direction of the toothed wheel |80.

g vThe shaft'22 bearsboth female parts offthe two clutches V 23 and 24, -them'ale 'partsV being respecftively fastened on the shaft 20 and on the wheel led, so'that, by the working of these two clutches,

the ,shaft 22 can be rotated in either direction.'

This shaft'22 controls, by the intermediary of'beveledgears 25, an accurate lead screw 2t.Y A nut 2l, in mesh withthe lead screw'26, controls the longitudinal motion of a longitudinal slide 28 ofV the tool-holder. Y

3 The set of'change wheels I8, Ita, |85, |80 causes the rather slow .rotation motion of the lead screw for controlling the workingr stroke of the Slide 28; the setof toothed'wheels i9, |911, |921, |90, |9d on thecontrary causes the quick rotation of the lead screw for controlling Vthe return Amotion of the slide 28.

A cross vslide 29 is controlled by a cam 3i) iXed on the cam shaft t.V Aroller 31 vrolls on this cam and its motions are transmittedby controlling rods to a toothed sector '32 in mesh with arack V33 (Fig. 8) llo-cated within the vsupport 3. This rack islitted kvvitha'pin 35 '(FigQ) 'penetrating into a cam opening 36 of a latpiece '3'4 lmounted into a slide of the carriage'29. This flatpiece 34 crank 48 and iat piece 34 and pin 35 and radially displace slide' 29 to raise it substantially away from the work or lower it intocontact -with the work. After each work stroke, cam shaft 4 ad-` vances carn'! to aposition to raise roller 3| and its connecting rods and cause toothed 'sector 32 to Y move rack 33 and slide '29radially a little closer to the workpiecetoa sufficient depth so that the tool 'will take '01T another cut of metal.

The nut 27 controls the slide 28 by thel intermediary of adjustable transmission elements'pro-V vided Vtfniodify thev transmissionV ratio of the 'motions between the nut 21 and the slide 28.

` Tothis eiect, the nut'21 `isfastened on a slide Y 4!) slidingin a slot 4| lof 'thegfra'me Themetion of this slide is at afrightV angle tothe motionr of the slide 28.` This slide bears a guide 42 which canv beangularly adjusted (Figari and'6) andisr provided with an inclined `plane constitutedV by one Aofthejeilgesof a vSlot 42a Iin which a linger 443 slides, the 'finger -43 being` xedlyV secured yto la rod :44 adapted to'reciprocate in the aperture 44a'- in the `frame l. Hence, the rod 44 maybe VYaxially Thel toothed wheel lc is fastened on a shaft 2e which carries one part `oi"a; clutch23. The shaft 2l bears a second toothed wheelV4 |912 K 45a arranged in the form of circular arcs emj bodied in the base of the guide, in order to allow to tilt the vguide 42 at the desired angle with refsp'ectto the motion of thepushing rod 44.

n rThe threaded rholes formed in the slide 4e and i intended tov receive the screws 45, are arranged on Y i Va straightlinel'disposed at 99 withV regard to the :'mtionaxis'of the slider.v Y

` 1 -lzhef'slots in the form of circular arcs 45a are arrangedsymmetricallywith regard to the kslot 42a and have an angular lengtliof` about 135.

'Adjustablefstops "46 and .41 'mounted on *theY slide an; are intended for aanneming by means iof arbell crank lever 43, the flat Ypiece 345m ordertjo cause vthe engaging of the toolatth'e end of the return' stroke and Vits `release atthe endnfthe working stroke, FlatV piece 34 is'provided yat its ends adjacentV bellv vcrank leverj'48 Ywith a deep groove (Fig. 5) wherein 'slidablyts one endof bellcrank '48, perm'tti'ngsliding movement of flat piece 34 in tl'iedirectionv of itsthickn'ess along the end ofl bell crarik48.

Anadjustable stop A4! mounted on theslide 4|! is'provided to effect thechange in the rotation di'- rec'tionlcftheleadscrewfat the end 'of'the workf ing stroke of the tool. To'this purpose the stop andthe throwing in of theclutchY 24.

Adjustable stopsiri and "51d,Y als() mounted oni the Islide '49, are intended to'cause the reversing of Athe rotation jniotion'of the lead screw 2b* at the endof the returnstroke of lthe tool, yas well as 'the automatic ls'toppingfof the whole VVdevice whenthescrew thread cutting operation is'comn pleted.

'To this-purpose; the stop El acts at'the endof v the return stroke cna lever 52.* in fsuch a way as to cause simultaneously /therthrowing'out of male parts of. both-clutch l23, and clutch -24 andV this'arm of bell crank lever "52 is 'spring-urgedjto when once set ftoclose clutch 2'3 Vagainst the' gear of the clutch 24 and the .throwingin of'ge'ar of the clutch 23.

An arm of bell crank lever 52 slottedly engages av pin carried by 'shaft 22 which Ycarries the fen'ormall-y`-open clutch 5232- and close A'c'li'tcl'l 24. but

` spring, lis so held fby a latchterminal ononafrm y ofbell crank'fleverlili.

When nut 21 *has travelledftolits'lowest position (Figure l2); v'itcausesisto'p 5| carriedb'y vslide 4@ 55 to apply pressure to 'th'elatch varm ofbell i cranklever 50 and cause its latch terminal .to enj gageand loc'k 'theend lof -bell 'crank 'lever y52 'and s-o'hold clutch123 engaged. When nutZ-'l and slide 40 ihavenearlyreached thel'upperfend of their'. travlKFig. 2), stop 4S engages-the stud on the upper end cf "bell crankr lever-BD and "throws the lower ilatch end ofbellcrank'lever out of engagement withtheespingiurged 'endof bell-crank i, lever 52 which permitsfthe''springto urge 'lever reto-neen durch 2a andenes-durch 2li;

At the end of each return stroke, the stop 5|a acts on a lever 55 which, by an intermediary of a set of rods, acts on a lever 5S. The extremity of this lever 5S thrusts against a pin 56a iixed on the lever l2. At each return of the slide 28 to the starting working position, the lever 56 is released from the pin 55a. However, the clutch i4 cannot be released, because the lever l2 is still maintained in position by the lever 8.

During the return of the tool to its initial working position, between successive runs, the cam S displaces the slide 29 in direction of the spindle in order that, when the tool engages, it cuts out a chip.

During the last return stroke of the tool, or during the last run, the cam face ita thrusts against the linger l, and moves the lever 8 to the position, shown on the drawing, so that the element rests no longer on the extremity of the lever I2. Thus, when the stop 5|a engages the lever 5E and rotates it about its pivotal point, the lever et is released from the pin 56a and the lever l2 becomes free and can be brought, under the action of a spring (not shown) to the position illustrated in the drawing. The displacement of the lever l2 throws out the clutch l!! and stops the further operation of the device.

it is clear that the pin 56a and the link t6 together with its cooperating kinematic connectors may be omitted, the stopping of the device being then dependent upon the control exercised by the cam face Ita at the end of the return stroke of the slide 28. Operation under the latter type of control is not however highly satisfactory as it is diiiicult to obtain the correct position of the slide 23 for commencing work on the next piece.

The sets of toothed wheels arranged between the spindle ilo', bearing the workpiece and the shaft 253 are interchangeable, so as' to effect a rotation speed ratio of both these two shafts which is approximately equal to the ratio existing between the pitch of the lead screw and the pitch of the screw thread to be cut. By tilting the guide Ll?. more or less-with respect to the motionaxis to the pushing-rod 4G, it is possible to modn ify the motion ratio between the nut 2l in mesh with the lead screw 26 and the longitudinal carriage 28 and thus to correct and eliminate the error or" pitch due to the ratio of the rotation speeds of the spindle Ila and of the shaft 2li, which, for some screw threads, cannot beV taken equal to the rati-o of the pitches.

As it appears, it is possible to'give the guide 2a all the tilts, from its right angle position with respect to the motion-axis of the pushing-rod d4 up to a point substantially parallel to this axis. Y The motion ratio between the nut 2'! and the pushing rod 44 can thus vary from Zero up to a lrelatively large value. It is clear that both these extreme positions are not actually used; it is however interesting to note that, for the tilts` as practically used, included within a tilt of 45 and the right angle position on the motionaxis of the pushing-rod 44, the motion ratio is smaller than l. Consequently, by choosing a speed ratio'between the spindle lla, and the shaft 2i! equal to a multiple of the ratio between the pitch or the lead-screw and the screw thread to be obtained, and by tilting conveniently the guide Q2u, it is possible reduce in the same proportion the thrust of the nut 2l on the lead screw during the working of the tool, and thus to reduce the wear of the lead-screw.

Finally, as it appears from Fig. 6, the guide l52a can be tilted at an angle of more than 45 on each side of the perpendicular to the motion of the pushing rod 44. Thus, by simply setting the position of the guide, it is possible to invert the displacement direction of the slide 28. This means howeverv a very substantial advantage as it is possible to work the same single screw thread by letting revolve the spindle in the'right hand or left hand direction. To accomplish this operation it is only necessary to insert or to remove one supplementary toothed wheel between the wheels I1 and I6, according to the rotation direction of the spindle, in order to provide the slide 40 with the same displacement direction for the control of a working run and to avoid an inversion in the control. This fact confers on the lathe a much wider working possibility, since being no longer compelled to apply a given direction of rotation to the spindle for cutting a right hand or a left hand screw thread, it is possible to operate simultaneously with screw thread cutting, a turning off, a bearing work, or other operations.

The arrangement shown in Fig. 2 has some disadvantages. Thus, for an example, when the stop 5| acts on lever 52, it is possible that, ater the releasing of the cone clutch 24, the inertia of the parts in rotation might not be suiicient in order that this stop 5| insures the meshing of both parts of the claw-clutch 23,

In order to eliminate this inconvenience, it is possible to employ a device having instantaneous motion in both displacement directions, and controlled by the stops 5| and 49. Many of these contrivances have been manufactured. In these devices, an element controlling the clutches is usually submitted to the action of an auxiliary control mechanism controlled, generally speaking, by springs. These latter might be put under tension, for example by the stop 5|, and provided with a bolt to keep the control elementl of one of the clutches in one of their positions. At the end of the stroke, the stop 5| can release this element, which, under the action of the control mechanism, promotes the releasing of one of the clutches and the throwing in of the other one.

Such a device is shown in Fig. 3. The lever 52 is pivoted on an axle 60, fastened on the bed i and bears two arms 52a and 52h. An element 6| for controlling the clutches is pivoted on the axle 60' and consists of a lever 6|, one arm of which is disposed between the arms 52a and 52h. This lever 6| is tted with a pin 62 intended toI work with a double bolt comprising two hooks 63a. and 63h which are pivoted On a xed part 64a and 64b. They are connected together by a spring G5, which tends to maintain the hooks downwardly, that is in contact with the pin S2,

The other end of this level 6| is fork-shaped. On each arm of this fork are pivoted the levers 66, each of which are provided with a ringer Sl penetrating into a groove 68 of a bh SQ, this latter being fastened on the female parts of the clutches 23 and 24. Rods 19, adjustable in length, allow the maximum distance to be set between the extremity of the arms of the fork and the extremity of the levers SES. These rods lil are rigidly xed on the extremity of the levers @e and slide into openings made on the extremities of the arms of lever 6|. Nuts 'll allow for the adjustment of the length of the rods which are connected to the levers 6o for the releasing of the cone-clutch 24. Springs 12 tend to maintain the maximum distance apart between the extremity of the arms of the leve;` 6| and the extremities of the levers 66. Each arm 52a. and 52h is prosatisfies t 7 videdfon fits' 'extrerrii'cy with a; -ngr tr-:115k which latter fis submitted .'t'o the.=a`ction fof affconrpression ispring flocated leachl 'in a bushing 13b. In addition 'these arms larg/provided with an adjustable stop v'hlir-Jltb, intend'elfto''releasef lever trlv` by thrusting againstl'the-fhooks iafand' 53h inorder to compelthem to Irookfat the tretquired-momentagainstthe actionfff a'l'spingiia;

Tnisdevice worksiasfollows: Y

The lever 52 is controlled either liv-*thestop V51| at theend of the return stroke, or byfthestcipy #.9 throwing out latch lever ia't 1 tnelend of-tlie working stroke.

fIn the 'position shown in Fig. f3, the tlutc'n y23 is in 'thrown-in position; 'the tool makes, fthe'refore, a working run. Somewhat Inicio-11'sthelend:v of the working run, the stop iwi-acts 'under the' lever nwan'd tends-to oscillate lit `a -counterclockwise direction. Tne'latch fend 'of lever 15%: releases -1ever52 =an finger 15athrusts, against the `lever v6 l and the vra'ction'ottlflestop 'compresses the spring located within the bushing'a?.

Y the endof -tlie working stroke, 'the stop 'Ma frocks the hook F63a', which is -in contact with the pinA 62. This oscillation releases the hook 'andr al'so releases the lever 611. This latter 'oscillate'siinfa counter-clockwise direction, under'th'e 'action di Y Vin position by the hook 1631) `inc`or1`tact with he pin -6-2'. At the end ofthe return-stroke, thestop 5| acting on the lever '52 Acauses ith'erev'erse nio-'- tion. The `'levers L(it, instead oi' being pusn'd'llov thesprings 1'2 fare pulledf-by the rods 1B.

l It appears that Adue-to this' elastic 'connection between -`.theflevers `til and 4theflex/"ens "E6-,lit is pols# sible 'to adjust Very 'easily fthe Specific b'lfes'slilfeoh the 'cone clutch, so as Ito dictan-1ia@osi-tive-'carri7 of the 'shaft E2. Moreover, this elastic con e'otion rallows V'to compensate for ltlfl'e "wear of Ithe coupling and confers there-fore Vto Tth'e whole' devicegreatvworkingreliability. I

l In the embodiment according t the device for the llathe-has 'been designedfas-a tuifni-'f ingf-01T'contlivafnce.A l

VThis device is', 'oi Vcourse, 'Very innen fsiinpler than the fol'fiesflwn -lfi Fig. -1-, because Vtfili'Sr` case, all the @necessary controlling `el'eine'nts for cutting out the screw thread :by Several ril'ns, canbelomitted. Y

The frame l! is zsed `on th`e'1ai'i'lfesmeans of 'the scie-ws 2. iframe 'isprovides witnfa groove 4I 'in which 'a carriageil slides', -`this lait'- ter bearing t'the Iangularly adjustable fglide "42, The motions `of this carriage -are .controlled a ilat cam '8U secured to the-'Cain shaft' 2i.

- cam 8@ has a snira-l prol'e'on which rolls 'a 'roller el, the menons yof which are transmitted fte 'the carriage by the 'intermediary of a' 'set 'of 'rods controlling e toothed sector 'e2 in meen with, el rack 8f3'o`n the carriage 'Eil f l As in the embodiment vdescribed aboveforigsf 1-"6, the/slide t3 is controlled by vthe 4pushing rod lili, the Vfinger i3l of which, Xed Aat its extremity, penetrates into 'the groove 42a oftlleguide 41,2.

l lSimilarly 4the slide nZ'Sfk-is controlledby a cam 8?! which is provided with ajcircular proleagainst which the roller 3l bears, -tne roller 3l being connectedby -a s et of rods to the toothed seca tor 32 in mesh with the rrack '33. This-latter is g n Should espeeisliyte frieten, that rire-control. 'of'the carriages `of the tool-'holders' can be oo'n-v Two mbodiineritsfof this 'invention' rrrhave been` l desc-iibed above: and are offered "ne'relyns exam'- 'Y ples thereof; vhowever, it `isiclear that-otherfernr bbdlments .-of the inventionr may be conceit/edf wl'lich` will 'fall within the 'scope `of this fin-vene y s tion. f

structed according. to ractual requirementsl and. i be adaptedfeasily"tofdifferenttypes of lathes.,

2 to 'have grfeat advantages.

supplementary "turning olliv or traversing ieper-aev "Ihisfdevide 'being equipped viii/'itin Tits own Ftool holder, permits the disposition ofpan auxiliary` tool-'holder'fon the lathe which-:has Vbeen shown Inv fact due to tlli's auxiliary 'tool-holder, it is possible 'to perform "a tion, the'cuttlng: ofa screw Ithi-eadar1d a tra-vers'-V l ingioperationf'on the same workpiece, 'witliout it being necessary `to fuse the 'rear t`oo`1=holder; v VThis auiiliary tool-holder'eliminates' nfmany-cases i a, re=setting-operation. Thus'great losses of time, Y

" due toffthe 're-setting operation jand'inanufacturtion, are eliminated.

ing errors due 'toa lack of. accuracy, whencentering the workpi-eoeiduring 'theresetting"opera-V Tliis arrangement lallows oneto 'use/the auX- iliary 'tool-'holder simultaneously 'with "any 'other tool-holder of the lathe. lMoreover, each oar-,V

nage-of theauiciliary tool-holder being controlled quiteiindepend'ently of the other tool-li'eldersfof tll'elathe, the setting in -tl'ieV working position f the :auxiliary tool-'holder as well as the feed of tion, the auxiliarytool-holder'is completelyout this latter can be started at the very moment required during 'several 'working 'operations to'V which the'workpiece vis submitted. l

It is to be inoted, that, 'in its-inoperative 'posiof the way'. infact, 'the -cross-slides @are `V corn- 1 pl'etelyrwithdrawn and the' traversing carriage is idisposedi'n `its working `starting position. Conse' quently, fin its linoperative fposition, rthisfa-nxiliarly l tool-:holder does not interfere in any way c .the yniotion of the "front andY rear tool-inolcers AV and AR, 'nor with :the motion of the 'vertical toolliold'enV, and- 'of that of 'the turret V(f'not shown).

- In Fig. 8,' the 'main tool-holdersrof 'the lathel f are shown, that. is, tneyfront.toolholderrAl/f, tlil'e 1 rear tool-fholderfAR andtheverticaltooleholder As a matter of fact,ftlle 'lathe can also' b equipped with auxiliaryrperting. surfacing er eutl having a work spindle and including a, snizgport';V

an auxiliary tool holder, a longitudinal "slideand, a radial islide for slidably mounting saidt'ool nold'- l er V`on lsaid support adjacentV 'said` work'is/pindle and fmovi'ng said holder respectively parallel'` 'or perpengieuiar with refereneetesaid spindle,"elisjplacing means ldisplaceable between two termi;v

nal positions, flrst Aconnecting means connecting seid `-eisencmg. means te sais longitudinal slide,

transmitting controll'ably` jreversable motion rneans driven b'v ksaid work spindle and adapted Y and said tool holder radially away clear from the work piece during return longitudinal movement of said tool holder or to move said radial slide and said tool holder radially toward and into working position with the work piece during the cutting stroke of said tool holder, and means actuatable by arrival of said displacing means in its terminal positions for reversing the direction of motion transmitted by said reversable motion transmitting means to said displacing means.

2. In an attachment for an automatic lathe having a work spindle and including a support, an auxiliary tool holder, a longitudinal slide and a radial slide for slidably mounting said tooll holder on said support adjacent said work spindle and moving said holder respectively parallel or perpendicular with reference to said spindle, displacing means displaceable between two terminal positions, iirst connecting means connecting said displacing means to said longitudinal slide, controllably reversable motion transmitting means driven by said work spindle and adapted to selectively continuously transmit to said displacing means motion in either of two opposite directions, second connecting means actuatable into one of two different actuating positions by arrival of said displacing means into one of its said terminal positions and adapted in its said two positions to respectively lift said radial slide and said tool holder radially,T away clear from the work piece during return longitudinal movement of said tool holder or to move said radial slide and said tool holder radially toward and into working position with the Work piece during the cutting stroke of said tool holder, means actuatable by arrival of said displacing means in its terminal positions for reversing the direction of motion transmitted yby said reversable motion transmitting means to said displacing means, a cam shaft driven by said work spindle, a cani carried on said cam shaft, and radial slide motion transmitting means actuatable by said cam and connected to said radial slide and adapted upon return of said tool holder to the initial point of its cutting stroke to radially advance the position of said radial slide through a distance corresponding to the depth of metal cut on one cutting stroke, so that the cutting tool continues to cut metal on successive cutting strokes.

3. In an attachment for an automatic lathe having a work spindle and including a support, an auxiliary tool holder, a longitudinal slide and a radial slide for slidably mounting said tool holder on said support adjacent said work spindle and moving said holder respectively parallel or perpendicular with reference to said spindle, displacing means displaceable between two terminal positions, first connecting means connecting said displacing means to said longitudinal slide, controllably reversable motion transmitting means driven by said work spindle and adapted to selectively continuously transmit to said displacing means motion in either of two opposite directions, second connecting means actuatable into one of two diiierent actuating positions by arrival of said displacing means into one of its said terminal positions and adapted in its said two positions to respectively lift said radial slide and said tool holder radially away clear from the work piece during return longitudinal movement of said tool holder or to move said radial slide and said tool holder radially toward and into working position with the work piece during the cutting stroke of said tool holder, means actuatable by arrival of said displacing means in y10 9/ its terminal positions for reversing the direction of motion transmitted by said reversable motion transmitting means to said displacing means, a cam shaft driven by said Work spindle, a first cam carried on said cam shaft, radial slide motion transmitting means actuataible by said cam and connected to said radial slide and adapted upon return of said tool holder tothe initial point of its cutting stroke to radially advance the position of said radial slide through a distance corresponding to the depth of metal cut on one cutting stroke, so that the cutting tool continues to cut metal on successive cutting strokes, a second cam carried on said cam shaft, and disconnecting means actuatable by arrival ofv said second vcam into a predetermined work termination position and by arrival of said displacing means into a terminal position thereof for disconnecting said reversable motion transmitting means from said Work spindle.

4. In an attachment for an automatic lathe having a work spindle and including a support, an auxiliary tool holder, a longitudinal slide and a radial slide for slidably mounting said tool holder on said support adjacent said Work spindle and moving said holder respectively parallel or perpendicular with reference to said spindle, displacing means displaceable between two terminal positions, rst connecting means connecting said displacing means to said longitudinal slide, controllably reversable motion transmitting means driven by said work spindle and adapted to selectively continuously transmit to said displacing means motion in either of two opposite directions, second connecting means actuatable into one of two different actuating positions by arrival of said displacing means into one of its said terminal positions and adapted in its said two positions to respectively lift said radial slide and said tool holder radially away clear from the work piece during return longitudinal movement of said tool holder or to move said radial slide and said tool holder radially toward and into working position with the work piece during the cutting stroke of said tool holder, and means actuatable by arrival of said displacing means in its terminal positions for reversing the direction of motion transmitted by said reversable motion transmitting means to said displacing means, said second connecting means comprising a bar actuated by said displacing means and having a cam surface, and a pin carried by said radial slide and engageable with said cam surface of said bar for moving said radial slide and said tool holder outwardly away and free of the work piece on the return stroke of said tool holder or for moving said radial slide inwardly toward the work pieces on the cutting stroke of said tool holder.

5. In an attachment for an automatic lathe having a work spindle and including a support, an auxiliary tool holder, a longitudinal slide and a radial slide for slidably mounting said tool holder on said support adjacent said work spindle and moving said holder respectively parallel or perpendicular with reference to said spindle, displacing means displaceable between two terminal positions, rst connecting means connecting said displacing means to said longitudinal slide, controllably reversable motion transmitting means driven by said work spindle and adapted to selectively continuously transmit to said displacing means motion in either of two opposite directions, second connecting. means actuatable into one of two different actuating positions by 1 131 aiival off said@ displacing means. into-J one-oftits saidzzteiininal positionsan adapted in its-said working-1 position with the Work piece. during'the outting stifokefof said tool'- hold'er.means actuatab1e-bi5arrival ofvsaid; displacingl meansinvitsy terminal positions for.- reversngfthecillrectiony of motion transmitted by Asaid: reversa-ble motion tnanemittinga means to i said:A displacingmeans, :aV

VcamA shaft driven `loyf said' Wonk spindlei a cam icair-iedon said'camshaft,-andlradials1id'emotion tiansmitting' means 'actualizable/by! rsaidi cam; and

connected; to said radial Vslide-and adapted upon 'return of saidftoolf l'ioldePftor the linit-,iai point of itsVoutting strokeY to radially advancetheY position of said-1radalA slide through-a distance oorre- 1 spnding'to 'the depth. ome'tal outononaoutting stoke,` so that the outtingfvvtoolf continues to Aeut metal on successive cutting StIYQKes-Saidwradial motion transmitting meansi comprisingfa toothed nnnlls'nnonstormn.

File-off this 'pata-mt:v A' A UNIFIED :RATE-'NTS y Number Name f Date Y @219;781'3 Flanders fMan; 2.0;;1917

' `132421,583V VNet5/"ton,eta-l". ;ct.i9,;f19,l:7 g-rg24833l72 Groeneet al'. .'Nov./:27.g 119.17 113420,'683 Bright. 'June 2U; 1=922 lfl Lovely-i July-31, 1928 ;1;,639;0901 Johnsonv Alug; 19,27 `7;,'865352-71 Lovely Julys, .1932 llgol'lg68' rvLovely' NrnnV 1f, 19727 21379171041 lfSvensorl Man; y2li; H331 `2,343,914' Lloyd Mar. 14:',19ft4z FOREIGN Number Y ,Country "Dalia i 52.11359 Britain May-30; 119% Y 

